We are now experiencing a slight warming trend that has raised the average global temperature by about 1.5 degrees Fahrenheit since 1850.
Yes, the carbon dioxide content of the atmosphere, now about 340 parts per million (0.034 percent), has increased by some 14 percent over the last 100 years. There is such a thing as a greenhouse effect; it is misnamed, but it is demonstrable in the laboratory.
In order to try to explain the warming-by greenhouse or some other effect-honest science, untainted by politics or ideology, would accept a theory that explains many observed phenomena, is contradicted by none, and surpasses its rivals in simplicity.
The theory that attributes the warming to carbon dioxide, due to fossil-fuel burning, rests on shaky data, is contradicted by the historical record, and has some rival theories to contend with; its overriding advantage over other theories is that it gets all the publicity.
THE GREENHOUSE EFFECT
The greenhouse effect consists of the following: White sunlight contains all the colors of the spectrum. If it falls on a red Stop sign, the red is absorbed and the rest of the colors are then scattered back into the sky or to other objects. Stop signs warm up during the day, but at night they cool, releasing their heat as infrared radiation. If the atmosphere were perfectly transparent, as much energy would be radiated back out into space as had arrived from the sun, and the earth’s heat balance would be maintained. But some gases, notably carbon dioxide (CO2), methane and ozone, absorb infrared (heat) radiation. These gases let in most colors of the spectrum, except infrared; the other colors are then changed to infrared and trapped between earth and sky.
No serious scientist would doubt the existence of this effect, which can be demonstrated and measured in the laboratory. But this is, by far, not the only effect that can lead to heating of the atmosphere. The unresolved question then becomes: What is the extent to which the greenhouse mechanism is responsible for the warming?
It is not, for example, responsible for the warming of a greenhouse. As early as 1913, experiments showed that the temperature difference between greenhouses with glass and (heat-transparent) quartz roofs was insignificant: greenhouses do not get warm by the greenhouse effect, but by lack of ventilation (as one can also see by opening a window in a moving car that has been standing in the sun).
WARMING TREND THEORIES
Quite similarly, there are competing theories explaining the warming trend. An eminent British scientist, J. Lovelock, has long pointed to the interaction between climate and biosphere: as the plankton and other living organisms thrive in a warm climate, the earth and its oceans reflect more of the incoming sunlight, so that the climate cools again and a slow oscillatory process sets in. (This so-called “Gaia” theory is now gradually gaining acceptance.) Dr. Hugh Elsaesser of the Lawrence Livermore National Laboratory in Livermore, Calif., points out that convectional heat transfer far exceeds the radiative effects of the orthodox greenhouse theory. Dr. S.B. Idso of the Department of Agriculture’s Research Service in Phoenix, Arizona, maintains that the selective opacities of CO2 and water vapor will screen out much incoming solar radiation that it overcompensates for orthodox greenhouse effects and leads to a net cooling of the planet.
The alternative theories have little chance of being discussed in public: if they do not preach doomsday or accuse industry, they have little chance of making it into the Sunday supplements. Comparing the relative importance of the greenhouse effect with these alternatives is not easy. Carbon dioxide circulates in nature: it arises in photosynthesis, burning and other processes, and it is absorbed by the seas and decomposed by plant respiration. If we knew the exact amounts circulating through each channel, the carbon budget would be balanced; in fact, no less than 30 percent of it is still unknown or under dispute. Suppose your company were losing money. Could you, pinpoint the causes if your balance sheets contained blanks amounting to 30 percent of the total? The obvious answer is no. Nor can we, as scientists run experiments (to see what happens without fossil-fuel burning). We can look at the historical record.
The natural temperature fluctuations over the centuries are clearly not caused by the burning of fossil fuels. Ice-core drillings and analysis of marine sediments show sudden, unexplained jumps of atmospheric CO2 concentration over the last 16,000 years-and it does not correlate with temperature cycles. In more recent times, ice drillings in India’s Himalayas revealed a high CO2 content from the late 17th century-just about the time when the earth went through the “little ice age” (including the harsh winter of 1683-1684, vividly described in Richard D. Blackmore’s novel, Lorna Doone). More recently still, fossil-fuel burning increased during the cooling period of 1950 to 1970.
But these are not the only difficulties. Carbon dioxide (and other “greenhouse gases” such as methane) is produced by a variety of sources other than fossil fuels (including those used in transportation). About as much CO2 is contributed by deforestation-the destruction of a CO2 sink-in the Third World. (This has been known to scientists for decades, but is only now being admitted by the “environmentalist” lobbies, whose main thrust is anti-industrial.)
More important, it seems unlikely that any man-made activity could be significant in comparison with the vast quantities of CO2 and methane released by volcanoes, swamps, animals and other members of pristine nature. For example, the CO2 released by the digestive process of termites alone is estimated to be 10 times higher than that due to fossil-fuel burning. This criticism is sometimes rejected on the grounds that termites are normal participants of the carbon cycle who have always been there, whereas fossil-fuel burning now artificially releases CO2 from hydro-carbons formed millions of years ago. But apart from the illustration of the quantities involved, the argument does not hold for the methane produced by the digestive process (belching) of ruminating animals, which again is estimated to be of the same order as fossil-fuel burning. The world’s cattle population has not “always” been there: been boosted by man, and in the industrial countries of the Free World, and has been rising, much faster than the populations of those countries.
Now, beef-eating is clearly a luxury that could be dispensed with far more easily than the energy now obtained by burning fossil fuels; in addition, the energy conservationists would have to notice that beef production (especially of grain-fed beef) is vastly more inefficient than the production of cereals, vegetables or, even, fish. In its fear of the alleged dangers of the greenhouse effect, the environmentalist lobby would therefore, more logically, have to advocate the extermination of cattle than the abolition of fossil fuels. (And in their love of petty arguments, they would have to point out that the grass consumed by cattle is a CO2 which again is estimated to be of the same order as fossil-fuel burning. The world’s cattle population has not “always” been there: been boosted by man, and in the industrial countries of the Free World, and has been rising, much faster than the populations of those countries.
NUCLEAR POWER VS. FOSSIL FUELS
Better proof of that point is available. Foremost is the campaign against nuclear power. It is easy to demonstrate, not by computer simulations, but by readily available statistics, that per energy produced, nuclear power (and its entire fuel cycle) is vastly safer than the burning of fossil fuels or hydropower in terms of deaths caused and disease incidence. This fact is covered up by the environmentalist lobby (with the inadvertent help of the nuclear industry, which does not want to offend its best customers-the coal-burning utilities).
Environmentally, nuclear power’ is overwhelmingly more benign than fossil fuels; for example, with reprocessed and bred nuclear fuel, the same amount of electric energy is produced by disrupting 5,000 times less land than by burning coal.
Even in the case of the alleged greenhouse dangers, nuclear power is superior, since it does not produce any of the greenhouse gases (or the emissions allegedly responsible for acid rain). Yet the so-called environmentalists continue to oppose it. A single hot, dry summer has thrown them into a panic.
“Why nuclear power will not save us from the greenhouse effect,” in which they no longer use the “we cannot afford to wait until we are sure” line. Instead, they suggest conservation by coercive (not market) forces as well as “alternative” sources that, because of their inherent and unavoidable diluteness, cannot substitute for large-scale energy production.
More realistic opinion leaders suggest “another look at nuclear power.” However, nuclear power should be used, above all, because of its superior safety and healthfulness compared with other sources, and also because, when unobstructed by scare-mongering and costly delays, it is cheaper than coal (let alone oil).
It does not need shaky arguments like the greenhouse effect.
Dr. Petr Beckmann is Professor Emeritus of Electrical Engineering at the University of Colorado, publisher of the pro-science, pro-technology, pro-free enterprise monthly newsletter, Access to Energy.